People maybe foolish but in a sense that they know it would be beneficial for them if they invest in bitcoin. People believe in it's potential despite the bear market, risky but with a sure profit.
Indeed, after all we have different perspective, I don't know what will people say if it happened if the investors get what they expected gains.
Yeah, there are some foolish people who invested in Bitcoin without knowing that they could lose a lot of money and dive in immediately without any knowledge on what they are doing and these are those greedy people who often lose a lot of money and easily get affected by FUD from those media Fudsters. 
Always remember to invest at your own risk and invest only what you afford to lose.
